Date reference device.



PATENTED MAR. 28. 1905.

7 J. ANDREW. DATE REFERENCE DEVIGB.

'APPLIUATIOF FILED JULY 5, 1904.

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WITNESSES:

Wz'fomey UNITED STATES Patented March 28, 1905.

JAMES ANDREWV, OF SAYLESVILLE, RHODE ISLAND.

DATE REFERENCE DEVICE.

SPECIFICATION forming part of Letters Patent No. 786,177, dated March28, 1905.

Application filed July 5, 1904. Serial No. 215,417.

To all whom, it may concern:

Be it known that I, J AMEs ANDREW, a citi- Zen of the United States,residing at Saylesville, in the county of Providence and State of RhodeIsland, have invented new and useful Improvements in Date ReferenceDevices, of which the following is a specification.

his invention relates to date reference devices.

The principal object of the invention is to determine the day of theweek upon which a certain date in a certain month of a certain year of acentury occurred in the past or will occur in the future.

A further object of the invention is to arrange in convenient andcompact form the improved means for attaining the object firstspecified.

With the above and other objects in view, which will appear as thedescription proceeds, the invention resides in the arrangement ofsymbols and in the combination of parts hereinafter described andclaimed as a practical embodiment of the invention.

In the accompanying drawings, forming part of this specification, Figure1 is a view illustrating one side of a disk containing radiating columnsof figures representing the years of a century, together with thesymbols used in conjunction therewith. Fig. 2 is a similar view of adisk adapted to be mounted for rotation upon the reverse side of thedisk illustrated in Fig. 1. Fig. 3 is a view showing the arrangement ofsymbols and numerals upon the reverse side of the disk shown in Fig. 1.

The embodiment of invention illustrated in the drawings is adapted todetermine the day of the week oi any given date during the nineteenthand twentieth centuries. It will be understood, however, that the ideaof invention herein disclosed is capable with slight modification ofbeing utilized to determine the day of the week of dates in othercenturies than the two which have been chosen for convenience ofillustration.

Referring to Fig. 1, the numeral 1 indicates a disk, which may beconstructed of any suitable material. Radiating from the central portionof the disk is a plurality of columns formed by lines, such as 2.Arranged concentrically upon the disk 1 is a series of numerals rangingfrom 1 to 99, each representing one year in a century. It will beobserved that each column contains a plurality of the numerals orsymbols which represent the years of the century and that each numeralexceeds the next lower numeral in the column by twenty-eight units. Oneof the columns, such as 3, is utilized to indicate the last year of thecentury, such as year 1900. A series of arbitrarily-selectedsymbolssuch, for instance, as A, K, T, E, D, O, B, and X is arrangedaround the periphery of the disk 1 in the outer concentric circlethereof, as shown, each symbol being used several times to complete thecircuit. In the embodiment of invention illustrated the outer series ofsymbols in the circle 4 is used to indicate a year occurring in thenineteenth century, as will appear more clearly hereinafter. Similarsymbols representing the leap years of the nineteenth century arearranged in the inner concentric circle 5 of the disk. The yearsoccurring in the twentieth century are (:lesignated by a similar seriesof symbols arranged in the circle 6 of the disk, the leap years of saidtwentieth century being indicated by the similar symbols in the circle 7It will be observed that a single symbol X is used to indicate the year1900.

The reverse side of the disk illustrated in Fig. 1 is shown in Fig. 3.Arranged circularly upon said reverse side of the disk 1 is the seriesof symbols A, K, T, E, D, O, and B. the symbol X being arranged beneaththe symbol B. A series of numerals ranging from 1 to 31 and indicatingthe days of a month is arranged concentrically upon the disk, saidsymbols being placed in radiating columns between the various lettersof" symbols. It will be observed that each numeral in the radiatingcolumns exceeds the next lower numeral by seven units.

By means of a rivet or other suitable device extending through thecentral perforation 8 of the disk 1 a similar disk 9 (illustrated inFig. 2) is revolubly mounted upon the reverse side of said disk 1.

The disk 9 is formed with a plurality of perforations 10. Upon the disk1, between the perforations 10 therein, is placed a plurality of wordsor symbols indicating the months of the year. The names of the monthsare preferably arranged as illustrated in Fig. 2that is, the monthsJanuary and October between two of the perforations, May between thenext two, August between the next two, February, March, and Novemberbetween the next two, June between the next two, September and Decemberbetween the next two, and April and July between the next two. The daysof the week are indicated by suitable words or symbols arranged upon theperiphery of the disk 9, as shown.

In Fig. 2 the disk 9 is represented as revolubly mounted upon thereverse side of the disk 1 by means of the rivets 11. For this reasonthe radiating columns of numerals representing the days of the month inFig. 3 are visible through the perforations 10 of said disk 9, thesymbols on Fig. 3 being obscured by the intervening portions of the diskbetween the various perforations thereof. In other words, the symbolsare concealed beneath the portion of the disk 9 on which the wordsindicating the months of the year are placed.

Arranged as hereinbefore described the method of using the improveddevice is as follows: Let it be presumed that the user of the devicedesires to determine the day of the week on which the date July 4, 1803,occurred: The first step is to find the numeral 3 on the disk 1. Thiswill be found in the radiating column, indicated by the symbols K anc E.As the date, however, occurred in the nineteenth century, only thesymbol K,which is in the circle relating to the nineteenth century, isnecessary in cal-' culating the day of the week. Having found the symbolK, the device is reversed and the disk 9 is rotated until the portion ofthe said disk 9 on which the month July is marked covers or obscures thesymbol K. It is now necessary only to inspect the. numerals denoting thedays of the month, when it will be found that the numeral 4, whichcompletes the date July 4, 1803, lies beneath the portion of the disk 9marked Monday. In this way it is determined that the date July 1, 1803,occurred on Monday.

Should the selected date occur after February in a leap year theleap-year symbols in the circles 5 and 7 of the disk 1 will beconsulted. For instance, if the selected date were after Februaryin theyear 1832, the leap-year symbols K and B would be found at the bottom ofthe column. As the year would be in the nineteenth century, the symbol Bin the leap-year circle 5, which relates to the nineteenth century,would be used in the manner described to determine the day of the weekon which any particular day after February in the year 1832 occurred,this being accomplished, as previously indicated, by revolving the disk9 until the selected month covered or obscured the symbol B and thenascertaining the day of the Week which was above the desired date in themonth.

When it is desired to determine the day of the week of a date occurringin the year 1900, the disk 9 is rotated until the proper month coversand obscures the symbol K, which in the embodiment of inventionillustrated is arranged beneath the symbol B.

Having thus fully described the invention, what is claimed as new is 1.A date reference device comprising a member having columns of numeralsor symbols representing the years of a century, each column having acode-symbol and said member having on its reverse side code-symbolscorresponding with those on the columns, and numerals or symbolsrepresenting the days of the month; and a disk revoluble upon thefirstmentioned member and containing symbols or words representing themonths of the year and the days of the week, whereby when the year of acentury is selected in one of the columns and the second disk isrevolved upon the first until a selected month covers the symbolcorresponding with the symbol of the selected year, the selected day ofthe month will lie beneath the symbol in dicating the day of the week.

2. A date reference device comprising a member having radiating columnsof numerals representing the years of a century, each numeral exceedingthe next lower numeral by twenty-eight units and each column beingdesignated by a code-symbol, the member having on its reverse side aseries of code-symbols corresponding with those on the columns, andnumerals or symbols representing the days of the month; and a diskhaving perforations and being revoluble upon the firstmentioned member,said perforated disk containing symbols or words representing the monthsof the year and the days of the week; whereby when the year of a centuryis selected in one of the columns and the disk is revolved upon thefirst-mentioned member until a selectedmonth covers the symbolcorresponding with the symbol of the selected year, the selected day ofthe month will lie beneath the symbol indicating the day of the week.

3. A date reference device comprising a disk having radiating columnscontaining numerals indicating the years of a century, one of thecolumns representing the year 1900, a plurality of concentric series ofsymbols representing the common years and the leap years of twocenturies, and a symbol representing the year 1900; the reverse side ofsaid disk having symbols corresponding with the symbols representing thecommon and leap years, a symbol representing the year 1900, andconcentrically-arranged numerals representing the days of a month; and aperforated disk revolubly mounted upon the reverse side of thefirst-mentioned disk and having words or symbols indicating the days ofthe week and words or symbols arranged thereon between the perforationsand indicating the months of a year.

4. A date reference device having columns of numerals or symbolsrepresenting the years of a century, each column having a code-symbol,an arrangement of code-symbols corresponding with those on the columns,and numerals or symbols representing the days of the month; and a diskrevoluble adjacent to said last-named arrangement of code symbols JAMESANDREWV.

Witnesses:

F. L. ALLEN, J12, JOHN ANDREW.

